in kernel/cpu/sh4/fpu.c [174:387]
static int ieee_fpe_handler(struct pt_regs *regs)
{
unsigned short insn = *(unsigned short *)regs->pc;
unsigned short finsn;
unsigned long nextpc;
int nib[4] = {
(insn >> 12) & 0xf,
(insn >> 8) & 0xf,
(insn >> 4) & 0xf,
insn & 0xf
};
if (nib[0] == 0xb || (nib[0] == 0x4 && nib[2] == 0x0 && nib[3] == 0xb))
regs->pr = regs->pc + 4; /* bsr & jsr */
if (nib[0] == 0xa || nib[0] == 0xb) {
/* bra & bsr */
nextpc = regs->pc + 4 + ((short)((insn & 0xfff) << 4) >> 3);
finsn = *(unsigned short *)(regs->pc + 2);
} else if (nib[0] == 0x8 && nib[1] == 0xd) {
/* bt/s */
if (regs->sr & 1)
nextpc = regs->pc + 4 + ((char)(insn & 0xff) << 1);
else
nextpc = regs->pc + 4;
finsn = *(unsigned short *)(regs->pc + 2);
} else if (nib[0] == 0x8 && nib[1] == 0xf) {
/* bf/s */
if (regs->sr & 1)
nextpc = regs->pc + 4;
else
nextpc = regs->pc + 4 + ((char)(insn & 0xff) << 1);
finsn = *(unsigned short *)(regs->pc + 2);
} else if (nib[0] == 0x4 && nib[3] == 0xb &&
(nib[2] == 0x0 || nib[2] == 0x2)) {
/* jmp & jsr */
nextpc = regs->regs[nib[1]];
finsn = *(unsigned short *)(regs->pc + 2);
} else if (nib[0] == 0x0 && nib[3] == 0x3 &&
(nib[2] == 0x0 || nib[2] == 0x2)) {
/* braf & bsrf */
nextpc = regs->pc + 4 + regs->regs[nib[1]];
finsn = *(unsigned short *)(regs->pc + 2);
} else if (insn == 0x000b) {
/* rts */
nextpc = regs->pr;
finsn = *(unsigned short *)(regs->pc + 2);
} else {
nextpc = regs->pc + instruction_size(insn);
finsn = insn;
}
if ((finsn & 0xf1ff) == 0xf0ad) {
/* fcnvsd */
struct task_struct *tsk = current;
if ((tsk->thread.xstate->hardfpu.fpscr & FPSCR_CAUSE_ERROR))
/* FPU error */
denormal_to_double(&tsk->thread.xstate->hardfpu,
(finsn >> 8) & 0xf);
else
return 0;
regs->pc = nextpc;
return 1;
} else if ((finsn & 0xf00f) == 0xf002) {
/* fmul */
struct task_struct *tsk = current;
int fpscr;
int n, m, prec;
unsigned int hx, hy;
n = (finsn >> 8) & 0xf;
m = (finsn >> 4) & 0xf;
hx = tsk->thread.xstate->hardfpu.fp_regs[n];
hy = tsk->thread.xstate->hardfpu.fp_regs[m];
fpscr = tsk->thread.xstate->hardfpu.fpscr;
prec = fpscr & FPSCR_DBL_PRECISION;
if ((fpscr & FPSCR_CAUSE_ERROR)
&& (prec && ((hx & 0x7fffffff) < 0x00100000
|| (hy & 0x7fffffff) < 0x00100000))) {
long long llx, lly;
/* FPU error because of denormal (doubles) */
llx = ((long long)hx << 32)
| tsk->thread.xstate->hardfpu.fp_regs[n + 1];
lly = ((long long)hy << 32)
| tsk->thread.xstate->hardfpu.fp_regs[m + 1];
llx = float64_mul(llx, lly);
tsk->thread.xstate->hardfpu.fp_regs[n] = llx >> 32;
tsk->thread.xstate->hardfpu.fp_regs[n + 1] = llx & 0xffffffff;
} else if ((fpscr & FPSCR_CAUSE_ERROR)
&& (!prec && ((hx & 0x7fffffff) < 0x00800000
|| (hy & 0x7fffffff) < 0x00800000))) {
/* FPU error because of denormal (floats) */
hx = float32_mul(hx, hy);
tsk->thread.xstate->hardfpu.fp_regs[n] = hx;
} else
return 0;
regs->pc = nextpc;
return 1;
} else if ((finsn & 0xf00e) == 0xf000) {
/* fadd, fsub */
struct task_struct *tsk = current;
int fpscr;
int n, m, prec;
unsigned int hx, hy;
n = (finsn >> 8) & 0xf;
m = (finsn >> 4) & 0xf;
hx = tsk->thread.xstate->hardfpu.fp_regs[n];
hy = tsk->thread.xstate->hardfpu.fp_regs[m];
fpscr = tsk->thread.xstate->hardfpu.fpscr;
prec = fpscr & FPSCR_DBL_PRECISION;
if ((fpscr & FPSCR_CAUSE_ERROR)
&& (prec && ((hx & 0x7fffffff) < 0x00100000
|| (hy & 0x7fffffff) < 0x00100000))) {
long long llx, lly;
/* FPU error because of denormal (doubles) */
llx = ((long long)hx << 32)
| tsk->thread.xstate->hardfpu.fp_regs[n + 1];
lly = ((long long)hy << 32)
| tsk->thread.xstate->hardfpu.fp_regs[m + 1];
if ((finsn & 0xf00f) == 0xf000)
llx = float64_add(llx, lly);
else
llx = float64_sub(llx, lly);
tsk->thread.xstate->hardfpu.fp_regs[n] = llx >> 32;
tsk->thread.xstate->hardfpu.fp_regs[n + 1] = llx & 0xffffffff;
} else if ((fpscr & FPSCR_CAUSE_ERROR)
&& (!prec && ((hx & 0x7fffffff) < 0x00800000
|| (hy & 0x7fffffff) < 0x00800000))) {
/* FPU error because of denormal (floats) */
if ((finsn & 0xf00f) == 0xf000)
hx = float32_add(hx, hy);
else
hx = float32_sub(hx, hy);
tsk->thread.xstate->hardfpu.fp_regs[n] = hx;
} else
return 0;
regs->pc = nextpc;
return 1;
} else if ((finsn & 0xf003) == 0xf003) {
/* fdiv */
struct task_struct *tsk = current;
int fpscr;
int n, m, prec;
unsigned int hx, hy;
n = (finsn >> 8) & 0xf;
m = (finsn >> 4) & 0xf;
hx = tsk->thread.xstate->hardfpu.fp_regs[n];
hy = tsk->thread.xstate->hardfpu.fp_regs[m];
fpscr = tsk->thread.xstate->hardfpu.fpscr;
prec = fpscr & FPSCR_DBL_PRECISION;
if ((fpscr & FPSCR_CAUSE_ERROR)
&& (prec && ((hx & 0x7fffffff) < 0x00100000
|| (hy & 0x7fffffff) < 0x00100000))) {
long long llx, lly;
/* FPU error because of denormal (doubles) */
llx = ((long long)hx << 32)
| tsk->thread.xstate->hardfpu.fp_regs[n + 1];
lly = ((long long)hy << 32)
| tsk->thread.xstate->hardfpu.fp_regs[m + 1];
llx = float64_div(llx, lly);
tsk->thread.xstate->hardfpu.fp_regs[n] = llx >> 32;
tsk->thread.xstate->hardfpu.fp_regs[n + 1] = llx & 0xffffffff;
} else if ((fpscr & FPSCR_CAUSE_ERROR)
&& (!prec && ((hx & 0x7fffffff) < 0x00800000
|| (hy & 0x7fffffff) < 0x00800000))) {
/* FPU error because of denormal (floats) */
hx = float32_div(hx, hy);
tsk->thread.xstate->hardfpu.fp_regs[n] = hx;
} else
return 0;
regs->pc = nextpc;
return 1;
} else if ((finsn & 0xf0bd) == 0xf0bd) {
/* fcnvds - double to single precision convert */
struct task_struct *tsk = current;
int m;
unsigned int hx;
m = (finsn >> 8) & 0x7;
hx = tsk->thread.xstate->hardfpu.fp_regs[m];
if ((tsk->thread.xstate->hardfpu.fpscr & FPSCR_CAUSE_ERROR)
&& ((hx & 0x7fffffff) < 0x00100000)) {
/* subnormal double to float conversion */
long long llx;
llx = ((long long)tsk->thread.xstate->hardfpu.fp_regs[m] << 32)
| tsk->thread.xstate->hardfpu.fp_regs[m + 1];
tsk->thread.xstate->hardfpu.fpul = float64_to_float32(llx);
} else
return 0;
regs->pc = nextpc;
return 1;
}
return 0;
}